In haemodialysis the nephrologists are faced with sudden changes in blood pressure and haemodynamic fragility phases that have a multi-factorial origin; ultrafiltration, decrease in osmolarity with imbalance and correction of metabolic acidosis play a predominant role [13-19]. Despite this, and thanks to some artifices, with particular reference to calcium concentration in the dialysate [15], dialysate temperature [20] and ultrafiltration and sodium concentration profiles [18,21-24], pressure stability is guaranteed as a general rule. Some electrolytes, particularly sodium and bicarbonate, can be modulated in profiles with the purpose of better respecting the gap in osmolarity or concentration that is established during the haemodialysis session, but their haemodynamic effect still remains controversial [20,22,24].